KR102763855B1 - fuel treatment system and ship having the same - Google Patents

Abstract

The present invention relates to a fuel treatment system and a ship including the same, comprising: a fuel supply unit which supplies fuel discharged from a fuel storage tank to a demander; a fuel recovery unit which recovers surplus fuel returned from the demander; and a fuel treatment unit which collects fuel vented from the fuel supply unit or the fuel recovery unit, wherein the fuel treatment unit includes a plurality of absorption tanks which collect fuel using water and generate waste water, and the fuel vented from the fuel supply unit or the fuel recovery unit passes through the plurality of absorption tanks in sequence and is dissolved in water stored in the absorption tanks to change into waste water.

Description

Fuel treatment system and ship having the same {fuel treatment system and ship having the same}

The present invention relates to a fuel processing system and a vessel including the same.

Air pollution is becoming more serious worldwide, and climate change is occurring due to air pollution. Since pollutants emitted from ships have a significant impact on air pollution, the International Maritime Organization (IMO), the European Union, the United States, and others are strengthening regulations on pollutants emitted from ships to reduce air pollution.

As greenhouse gas emission regulations for ships are gradually strengthened at key milestones through 2050, it is expected that existing engines and fuels alone will be unable to comply with regulations on pollutants.

Therefore, as the strengthened greenhouse gas emission regulations for ships are applied, it is expected that the use of existing fossil fuels currently in use will be difficult, and it is very urgent to find alternative fuels that can satisfy the strengthened regulations in the future. Non-fossil fuels such as ammonia (NH3), biofuel, solar energy, and wind energy are being considered as alternative fuels.

Among them, ammonia is a chemical substance that can be produced, stored, transported, and supplied, and an ammonia ship that uses ammonia as fuel is being developed.

Existing ammonia ships store ammonia fuel as liquid, but ammonia has a boiling point lower than room temperature (atmospheric pressure, -33℃), so in order to store ammonia as liquid, the fuel storage tank must also have certain specifications. In addition, in order to maintain ammonia in a liquid state, the inside of the tank must be kept at a low temperature, so the storage tank must be cooled, and a lot of energy is consumed in the cooling process.

In addition, storage tanks for liquid ammonia may generate vaporized gas inside the tank, which may increase the pressure inside the storage tank and cause the tank to explode. In addition, if liquid ammonia leaks outside the tank, an explosion may occur, and there is a risk of casualties due to the toxicity of ammonia.

In this way, existing ammonia ships had limitations in terms of efficiency in terms of facility costs and operating costs in storing liquid ammonia fuel and supplying ammonia fuel to engines, and the safety of the facilities was also low.

The present invention has been created to solve the problems of the prior art as described above, and provides a fuel processing system that guarantees stable and reliable fuel supply when supplying ammonia as fuel for an engine, and a ship including the same.

A fuel processing system according to one aspect of the present invention comprises: a fuel supply unit which supplies fuel discharged from a fuel storage tank to a demander; a fuel recovery unit which recovers surplus fuel returned from the demander; and a fuel treatment unit which collects fuel vented from the fuel supply unit or the fuel recovery unit, wherein the fuel treatment unit comprises a plurality of absorption tanks which collect fuel using water to generate wastewater, and the fuel vented from the fuel supply unit or the fuel recovery unit passes through the plurality of absorption tanks in sequence and is dissolved in water stored in the absorption tanks to be changed into wastewater.

Specifically, the plurality of absorption tanks may have a relatively lower fuel concentration from upstream to downstream based on the flow of fuel vented from the fuel supply unit or the fuel recovery unit.

Specifically, the plurality of absorption tanks are stacked in the height direction, and the absorption tanks can be provided so that they can be separated from each other.

Specifically, the plurality of absorption tanks may include a first absorption tank having water stored therein and into which fuel vented from the fuel supply unit or the fuel recovery unit flows; and a second absorption tank having water stored therein and into which gas not absorbed into water in the first absorption tank flows.

Specifically, the first absorption tank is provided below the second absorption tank, and can be separated based on the second absorption tank when the fuel concentration in the wastewater is above a certain level.

Specifically, the fuel processing unit may include an nth absorption tank in which water is stored therein, gas that is not absorbed into water in at least the first absorption tank among the first absorption tank and the second absorption tank is introduced, and gas that is not absorbed into water inside is discharged to the atmosphere at a concentration below a predetermined level.

A vessel according to one aspect of the present invention has the fuel processing system.

The fuel processing system according to the present invention and a vessel including the same can efficiently supply ammonia to an ammonia engine and exhibit excellent performance in exhaust treatment, purging, etc.

FIG. 1 is a conceptual diagram of a fuel processing system according to a first embodiment of the present invention.
FIG. 2 is a conceptual diagram of a fuel processing system according to a second embodiment of the present invention.
FIG. 3 is a conceptual diagram of a fuel processing system according to a third embodiment of the present invention.
FIG. 4 is a conceptual diagram of a fuel processing system according to a fourth embodiment of the present invention.
FIG. 5 is a conceptual diagram of a fuel processing system according to a fifth embodiment of the present invention.
FIG. 6 is a conceptual diagram of a fuel processing system according to a sixth embodiment of the present invention.
FIG. 7 is a conceptual diagram of a fuel processing system according to the seventh embodiment of the present invention.
FIG. 8 is a conceptual diagram of a fuel processing system according to the eighth embodiment of the present invention.
FIG. 9 is a conceptual diagram of a fuel processing system according to the ninth embodiment of the present invention.
FIG. 10 is a conceptual diagram of a fuel processing system according to the tenth embodiment of the present invention.
FIG. 11 is a conceptual diagram of a fuel processing system according to the 11th embodiment of the present invention.
FIG. 12 is a conceptual diagram of a fuel processing system according to the 12th embodiment of the present invention.
FIG. 13 is a conceptual diagram of a fuel processing system according to the 13th embodiment of the present invention.
FIG. 14 is a conceptual diagram of a fuel processing system according to the 13th embodiment of the present invention.
FIG. 15 is a conceptual diagram of a fuel processing system according to the 14th embodiment of the present invention.

The purpose, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings. In this specification, when adding reference numerals to components in each drawing, it should be noted that, as much as possible, the same components are given the same numerals even if they are shown in different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

In the present invention, the fuel may be ammonia, but is not limited thereto. The fuel may include any kind of substance that has a relatively low boiling point and is water-soluble, such as methanol, ethanol, etc.

The present invention includes a vessel equipped with a fuel processing system as described below. In this case, the vessel is a concept that includes an ammonia carrier, a merchant ship transporting cargo or people other than ammonia, an FSRU, an FPSO, a bunkering vessel, an offshore plant, etc.

Although not shown in the drawings of the present invention, a pressure sensor (PT), a temperature sensor (TT), a flow sensor (FT), etc. may be installed in appropriate locations without limitation, and the measurement values by each sensor may be used in various ways without limitation in the operation of the configurations described below.

In addition, in the drawings of the present invention, straight lines represent paths through which various fluids such as ammonia, berries, and non-explosive gases move, and can be interpreted as pipelines.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

FIG. 1 is a conceptual diagram of a fuel processing system according to a first embodiment of the present invention.

Referring to FIG. 1, a fuel processing system (1) according to the first embodiment of the present invention includes a fuel storage tank (10), a fuel supply unit (20), a fuel recovery unit (30), an exhaust treatment unit (40), and a fuel processing unit (60).

The fuel storage tank (10) stores ammonia. Ammonia is used as a fuel consumed by a demand source such as an engine (E). At this time, the engine (E) may be an ammonia-only engine (E) or an ammonia mixed-fuel engine (E). Of course, in this specification, the engine (E) is interpreted as a mechanism that consumes ammonia to obtain energy, and includes turbines, etc. In addition, the demand source includes various consumers in addition to the engine (E).

The fuel storage tank (10) stores ammonia in a liquid state, and for this purpose, insulation may be applied to at least one side of the inside or the outside of the fuel storage tank (10). Alternatively, the fuel storage tank (10) may store ammonia at a high pressure to prevent liquefaction of the ammonia, and in this case, the low-pressure pump (21) of the fuel supply unit (20) described later may be reduced or omitted.

The fuel storage tank (10) may be provided to form a cargo hold inside the ship, or may be a fuel tank provided separately inside the ship or on the deck. One or more of these fuel storage tanks (10) are provided, and when a plurality of fuel storage tanks (10) are provided, ammonia may be consumed selectively or simultaneously.

A bunkering station (not shown) is connected to the fuel storage tank (10), and the bunkering station delivers ammonia from an external fuel source to the fuel storage tank (10). The external fuel source may be an ammonia supply source on land, or an ammonia bunkering ship at sea.

A pressure control unit (11) may be provided in the fuel storage tank (10). The pressure control unit (11) may be a PBU (Pressure Build-up Unit) that heats or vaporizes ammonia discharged from the fuel storage tank (10) and then injects it into the fuel storage tank (10) to increase the internal pressure of the fuel storage tank (10), or may be a supercooler that cools/subcools ammonia and returns it.

In addition, the pressure control unit (11) may be a re-liquefaction device (111) that re-liquefies gaseous ammonia (evaporated gas) discharged from the fuel storage tank (10) and returns it to the fuel storage tank (10). In the case of the re-liquefaction device (111), it may be connected to the fuel storage tank (10) by a gaseous treatment line (L11). The pressure control unit (11) may secure the stability of ammonia fuel supply by increasing or decreasing the internal pressure of the fuel storage tank (10).

The fuel supply unit (20) supplies ammonia from the fuel storage tank (10) to the engine (E). The fuel supply unit (20) can supply liquid ammonia from among the ammonia stored in the fuel storage tank (10) to the engine (E). In particular, considering the specifications of the engine (E) currently consuming ammonia, the fuel supply unit (20) is arranged to supply ammonia in a liquid state to the engine (E). Of course, the fuel supply unit (20) can variously adjust the state of the ammonia in response to changes in the specifications of the engine (E).

The fuel supply unit (20) includes a low-pressure pump (21). The low-pressure pump (21) is responsible for the function of withdrawing ammonia stored in the fuel storage tank (10) to the outside, and may be provided as a fixed-capacity type or a variable-capacity type (VFD).

The low-pressure pump (21) may be placed inside the fuel storage tank (10), but unlike the drawing, it may also be placed downstream of the fuel storage tank (10). Furthermore, as described above, the low-pressure pump (21) may be omitted depending on the type and internal pressure of the fuel storage tank (10).

Unlike in the drawing, the low-pressure pump (21) may be provided in multiple numbers to form a mutually back-up structure, and also, multiple low-pressure pumps (21) may be provided to operate simultaneously and share the load. Alternatively, multiple low-pressure pumps (21) may be provided in series to utilize a multi-stage pressurization method.

The fuel supply unit (20) further includes a high-pressure pump (22) and a heat exchanger (23). The high-pressure pump (22) pressurizes ammonia pressurized by the low-pressure pump (21) to correspond to the required pressure of the engine (E). As described in the low-pressure pump (21), one or more high-pressure pumps (22) may be provided in series or in parallel.

The high-pressure pump (22) may be provided as a variable-capacity type, and the load may be varied according to the measurement value of a flow meter that may be provided between the low-pressure pump (21) and the high-pressure pump (22). At this time, the flow meter may be provided at a location where the flow rate of excess ammonia recovered by the fuel recovery unit (30) is reflected.

The fuel recovery unit (30) described later can transfer excess ammonia discharged from the engine (E) to the high-pressure pump (22), but the high-pressure pump (22) does not preferably have gaseous inflow due to its specifications. Therefore, it is required that the ammonia upstream of the high-pressure pump (22) exists only in a liquid phase, and for this purpose, the temperature and pressure upstream of the high-pressure pump (22) can be effectively controlled.

For example, ammonia recovered by the fuel recovery unit (30) can be cooled, and the ammonia pressure upstream of the high pressure pump (22) can be maintained high to increase the boiling point of ammonia and suppress vaporization.

The heat exchanger (23) controls the temperature of ammonia. The heat exchanger (23) may be provided upstream of the high-pressure pump (22), that is, between the low-pressure pump (21) and the high-pressure pump (22). Alternatively, the heat exchanger (23) may be provided downstream of the high-pressure pump (22), and may be provided upstream and downstream of the high-pressure pump (22), respectively. The heat exchanger (23) may use a non-limiting medium such as glycol water (GW), seawater, clear water, or steam to control the temperature of ammonia in response to the required temperature of the engine (E).

The heat exchanger (23) may be a heater that heats ammonia. Generally, the required temperature of the engine (E) is higher than the storage temperature of the fuel storage tank (10) (below the boiling point of ammonia at atmospheric pressure), and since the temperature increase that occurs during pressurization of the low-pressure pump (21) and the high-pressure pump (22) is insufficient to meet the required temperature of the engine (E), the heat exchanger (23) may be used.

However, the heat exchanger (23) is installed upstream of the high-pressure pump (22) so that the temperature of ammonia can be appropriately controlled to prevent ammonia gas from flowing into the high-pressure pump (22). At this time, the heat exchanger (23) controls the heating temperature of ammonia in consideration of the recovery of ammonia by the fuel recovery unit (30).

The heat exchanger (23) can be supplied with heat and used to heat ammonia. That is, the heat exchanger (23) can be provided in a form that mutually exchanges heat between the heat and ammonia.

Alternatively, the heat exchanger (23) may be a water bath type heater in which ammonia passes through the inside of a water tank containing water. At this time, as the water bath type heater, a water bath type steam heater that heats the water inside with steam, or a water bath type electric heater that heats the water inside with electricity generated from a power generation engine (E), etc. may be used.

The fuel supply unit (20) is equipped with a valve for controlling the supply flow rate of ammonia, etc., just before the engine (E). At this time, such valve may be referred to as a fuel supply valve train (SVT).

In addition, a high-pressure pump (22) and a heat exchanger (23) included in the fuel supply unit (20) are provided, and a line that allows ammonia to flow from the liquefied gas storage tank to the engine (E) can be defined as a fuel supply line (L10).

The fuel recovery unit (30) recovers excess ammonia returned from the engine (E). The ammonia engine (E) currently developed or under development consumes ammonia in liquid form, but has a structure in which the excess is additionally supplied in order to stably supply the required amount.

At this time, the excess ammonia may pass through at least a part of the engine (E) and then be discharged from the engine (E), in which case the lubricating oil used in the engine (E) may be mixed with the ammonia. Therefore, the excess ammonia discharged from the engine (E) is in a contaminated state and is not desirable to be returned to the fuel storage tank (10).

However, since this surplus ammonia is consumable in the engine (E), the fuel recovery unit (30) transfers the surplus ammonia discharged from the engine (E) to the fuel supply unit (20). Specifically, the fuel recovery unit (30) can transfer the surplus ammonia from the fuel supply unit (20) to the high-pressure pump (22). This transfer of ammonia is performed by the fuel recovery line (L20). The fuel recovery line (L20) may be provided with a cooler (31), a collecting tank (32), etc.

The cooler (31) cools the excess ammonia discharged from the engine (E). Since the excess ammonia has passed through the engine (E), it may be heated by the heat generated by the engine (E), and if it is returned as is and flows into the high-pressure pump (22), it may cause the gaseous phase to flow into the high-pressure pump (22). Therefore, the cooler (31) cools the excess ammonia with fresh water, etc. and transfers it between the low-pressure pump (21) and the high-pressure pump (22) in the fuel supply unit (20), thereby preventing the ammonia gaseous phase from flowing into the high-pressure pump (22).

The collecting tank (32) is provided in parallel with a portion of the fuel recovery line (L20) and temporarily stores ammonia. The collecting tank (32) is branched and connected upstream of the high-pressure pump (22) based on the flow of ammonia delivered from the engine (E) to the high-pressure pump (22). The collecting tank (32) stores at least a portion of the surplus ammonia returned from the engine (E) and performs gas-liquid separation, thereby preventing the gas phase from flowing into the high-pressure pump (22).

In addition, the collecting tank (32) may be provided to remove lubricating oil contained in the excess ammonia. The collecting tank (32) may have a structure including a gas-liquid separator and a knockout drum. In this case, the excess ammonia first flows into the gas-liquid separator to separate the gas phase, and at least a portion of the liquid excess ammonia flows into the knockout drum to separate the lubricating oil. That is, the separation of the gas phase and the lubricating oil described above may be achieved by a separate configuration, but for convenience, a configuration implementing these functions may be included in the collecting tank (32).

The fuel recovery unit (30) is provided with a valve for controlling the return flow rate of ammonia, etc. immediately after the engine (E). At this time, such valve may be referred to as a fuel return valve train (RVT). In particular, the fuel supply valve train (SVT) and the fuel return valve train may be collectively defined as a fuel valve train (FVT).

The exhaust treatment unit (40) treats exhaust gas emitted from the engine (E). The exhaust gas of the engine (E) may contain various particles and environmental pollutants such as nitrogen oxides (NOx), and the exhaust treatment unit (40) can appropriately treat pollutants in the exhaust gas using filtering, chemical reactions, etc.

For example, the exhaust treatment unit (40) may be a selective catalytic reduction device (SCR (41)) or an SCR (41) uuber, etc. However, in the present embodiment, the exhaust treatment unit (40) may be provided to include at least an SCR (41) and may use ammonia or the like as a reducing agent.

The reducing agent used by the exhaust treatment unit (40) may be supplied separately from the outside, or may be delivered from the fuel supply unit (20), etc. That is, the fuel supply unit (20) can deliver at least a portion of the ammonia flowing toward the engine (E) to the exhaust treatment unit (40).

Therefore, the exhaust treatment unit (40) can use at least a portion of the ammonia supplied to the engine (E) by the fuel supply unit (20) as a reducing agent. To this end, a fuel delivery line (L30) can be provided between the fuel supply unit (20) and the exhaust treatment unit (40).

The fuel delivery line (L30) may be branched from the fuel supply line (L10) between the low-pressure pump (21) and the high-pressure pump (22), and may be provided with a filter and a pressure regulating valve (PCV). For reference, a filter and a pressure regulating valve for delivering ammonia to the SCR (41) may be defined as an ammonia delivery unit (44).

In addition, the fuel delivery line (L30) may pass through a dosing unit (42) to supply an appropriate amount of ammonia to the SCR (41). The dosing unit (42) may not only control the amount of ammonia supplied to the SCR (41), but also control the concentration of ammonia as a reducing agent.

For this purpose, the metering unit (42) can mix compressed air with ammonia. The exhaust treatment unit (40) can further include an air supply unit (43) for supplying (compressed) air to the metering unit (42), and the air supply unit (43) can be an air fan or an air compressor, etc.

The metering unit (42) can mix compressed air and ammonia and supply a reducing agent with an appropriate ammonia ratio to the SCR (41). Through this, nitrogen oxides in the engine (E) exhaust are efficiently removed.

The exhaust treatment unit (40) may include a fuel return line (L31) that returns from the fuel delivery line (L30) to the fuel storage tank (10). The fuel return line (L31) may recover some of the ammonia upstream of the metering unit (42) to the fuel storage tank (10). Through this, the exhaust treatment unit (40) may have a pressure control function for the fuel storage tank (10).

In particular, a return heat exchanger (45) may be provided in the fuel return line (L31). When the fuel storage tank (10) is at low pressure, the return heat exchanger (45) can heat at least a portion of the ammonia delivered to the fuel delivery line (L30) to restore the internal pressure of the fuel storage tank (10) to an appropriate level.

Of course, the fuel return line (L31) can be arranged to pass through the return heat exchanger (45) or at least partially bypass it, so that the exhaust treatment unit (40) can be used to maintain the pressure of the fuel storage tank (10) within a certain range.

Additionally, the fuel return line (L31) may be connected to the pressure control unit (11). The pressure control unit (11) may be a re-liquefaction device (111), and the fuel return line (L31) may transfer at least a portion of the ammonia flowing along the fuel delivery line (L30) to the pressure control unit (11) so that it may be returned to the fuel storage tank (10) after liquefaction/supercooling. This process may be performed when the internal pressure of the fuel storage tank (10) is high.

This exhaust treatment unit (40) can sufficiently purify the exhaust of the engine (E) and then discharge it into the atmosphere. The exhaust purified by the exhaust treatment unit (40) is discharged to the outside through a funnel having a certain height and treated so as not to cause harm to people.

The fuel treatment unit (60) can store ammonia discharged during a normal stop or emergency stop in a section where ammonia is stored or flows. The fuel treatment unit (60) can use water to efficiently treat ammonia.

Ammonia easily dissolves in water and is converted into ammonia water (waste water). Using this, the fuel treatment unit (60) can collect ammonia discharged from a fuel supply unit (20) or a fuel recovery unit (30) by dissolving it in water.

The fuel treatment unit (60) may be a scrubber (61) that sprays water onto ammonia so that the ammonia can be converted into ammonia water and captured. In addition, the fuel treatment unit (60) may be an absorption tank (62) that captures ammonia using water and generates ammonia water. Of course, the fuel treatment unit (60) may also be a form in which a scrubber (61) and an absorption tank (62) are combined.

The fuel processing unit (60) of the present invention will be described in detail in another embodiment with reference to FIG. 13 and the like, and a more detailed description will be omitted here. However, the contents of the fuel processing unit (60) described in FIG. 13 and the like can be applied to all embodiments included in the present invention.

In this way, the present embodiment supplies at least a portion of the ammonia supplied as fuel to the engine (E) to the SCR (41), and at least a portion of the ammonia delivered to the SCR (41) is heated or cooled and recovered into the fuel storage tank (10), thereby appropriately controlling the pressure of the fuel storage tank (10).

FIG. 2 is a conceptual diagram of a fuel processing system according to a second embodiment of the present invention.

In the following, the differences between this embodiment and the previous embodiment will be mainly explained, and any omitted parts will be replaced with the previous contents. Please note that this also applies to other embodiments below.

Referring to FIG. 2, in the case of the fuel processing system (1) according to the second embodiment of the present invention, instead of branching off from the fuel supply line (L10), the fuel delivery line (L30) may be extended from the fuel storage tank (10). In this case, a pump (not shown) for supplying ammonia as a reducing agent to the SCR (41) may be provided at the inlet end of the fuel delivery line (L30).

In addition, as described above, a filter and a pressure regulating valve can be installed in the fuel delivery line (L30). Additionally, a delivery heat exchanger (46) is provided in the fuel delivery line (L30) so as to appropriately control the temperature of ammonia supplied to the SCR (41).

FIG. 3 is a conceptual diagram of a fuel processing system according to a third embodiment of the present invention.

Referring to FIG. 3, the fuel processing system (1) according to the third embodiment of the present invention is similar to the first embodiment in that the fuel delivery line (L30) branches from the fuel supply line (L10) between the low-pressure pump (21) and the high-pressure pump (22).

However, in the case of the present embodiment, the fuel delivery line (L30) may be branched between the heat exchanger (23) and the high pressure pump (22) in the fuel supply unit (20), particularly downstream of the point where the fuel recovery line (L20) joins the fuel supply line (L10).

In this case, ammonia flowing into the fuel delivery line (L30) may have a state corresponding to the temperature and pressure of ammonia flowing into the high-pressure pump (22). Therefore, the pressure regulating valve provided in the fuel delivery line (L30) may generally perform a pressure reducing function.

FIG. 4 is a conceptual diagram of a fuel processing system according to a fourth embodiment of the present invention.

Referring to FIG. 4, in the fuel processing system (1) according to the fourth embodiment of the present invention, the fuel delivery line (L30) is additionally extended from the pressure control unit (11) compared to the case of the third embodiment.

The pressure control unit (11) may be a re-liquefaction device (111), and ammonia discharged as a gas from a fuel storage tank (10), compressed and cooled in the re-liquefaction device (111), and then just before being depressurized, may be delivered to the SCR (41) through the fuel delivery line (L30). Through this, the pressure control unit (11) of the present embodiment can prevent unnecessary depressurization and increase the re-liquefaction efficiency.

In this case, a filter and a pressure regulating valve are provided in the fuel delivery line (L30). The filter, etc. may be provided downstream of the point where ammonia flowing from the reliquefaction device (111) and ammonia flowing from the upstream of the high-pressure pump (22) can merge.

FIG. 5 is a conceptual diagram of a fuel processing system according to a fifth embodiment of the present invention.

Referring to FIG. 5, the fuel treatment system (1) according to the fifth embodiment of the present invention has an exhaust treatment unit (40) provided to deliver ammonia to the SCR (41) upstream of the high-pressure pump (22), similar to the third embodiment.

However, the exhaust treatment unit (40) of this embodiment can use a vaporizer (47) instead of a metering unit (42). That is, unlike other embodiments that supply ammonia to the SCR (41) in a liquid state, the exhaust treatment unit (40) can supply ammonia to the SCR (41) in a gaseous state. In this case, the exhaust treatment unit (40) can more efficiently control the flow rate of ammonia supplied to the SCR (41).

In addition, the exhaust treatment unit (40) can receive gaseous ammonia generated in the fuel storage tank (10) and deliver it to the SCR (41). Through this, the exhaust treatment unit (40) can relieve the overpressure of the fuel storage tank (10) and achieve the pressure control effect of the fuel storage tank (10).

FIG. 6 is a conceptual diagram of a fuel processing system according to a sixth embodiment of the present invention.

Referring to FIG. 6, the fuel processing system (1) according to the sixth embodiment of the present invention can vaporize ammonia in the fuel supply unit (20) and supply it to the SCR (41) as described in the fifth embodiment.

Furthermore, the present embodiment may be provided with an air supply unit (43) and an ammonia/air mixer (48) downstream of a vaporizer (47). An exhaust treatment unit (40) using an ammonia/air mixer (48) may dilute ammonia vaporized in the vaporizer (47) with air and supply it to an SCR (41).

In this way, the exhaust treatment unit (40) of the present embodiment can improve mixing efficiency by diluting ammonia with air. In addition, since the concentration of ammonia is lowered by dilution, the requirement for a safety system can be reduced.

In addition, the present invention may further include, as a separate embodiment, utilizing ammonia discharged from a fuel supply unit (20) or a fuel recovery unit (30) as a reducing agent.

That is, at least a portion of the ammonia delivered to the exhaust mast (not shown) is delivered to the SCR (41) by the exhaust treatment unit (40), thereby being used to purify nitrogen oxides and the like included in the exhaust of the engine (E).

FIG. 7 is a conceptual diagram of a fuel processing system according to the seventh embodiment of the present invention.

Referring to FIG. 7, the fuel processing system (1) according to the seventh embodiment of the present invention is different from other embodiments in that the collecting tank (32) implements a condensation function.

The collecting tank (32) of the present embodiment can implement the role of a condenser that receives and re-liquefies gaseous ammonia discharged from the fuel storage tank (10). The collecting tank (32) can store excess ammonia returned from the engine (E) in a liquid state. However, the excess ammonia flowing into the collecting tank (32) from the engine (E) is in a relatively high temperature state without passing through the cooler (31), but can be maintained in a liquid state due to high pressure, so the gaseous ammonia flowing into the collecting tank (32) from the fuel storage tank (10) can also be liquefied within the collecting tank (32).

The present embodiment can use a re-liquefaction device (111) as a pressure control unit (11), and the re-liquefaction device (111) can be equipped with a compressor (112) and a condenser (113) to re-liquefy gaseous ammonia discharged from a fuel storage tank (10).

At this time, the gaseous ammonia compressed in the compressor (112) is delivered to the collecting tank (32) through the gaseous delivery line (L12) and can change into a liquid phase under the internal pressure of the collecting tank (32). That is, the ammonia generated in the fuel storage tank (10) flows into the collecting tank (32) through a part of the gaseous treatment line (L11), the compressor (112), and the gaseous delivery line (L12).

However, in order to increase the liquefaction efficiency of gaseous ammonia, the collecting tank (32) may be supplied with liquid ammonia from upstream of the high-pressure pump (22) in addition to the high-temperature surplus ammonia supplied from the engine (E). For this purpose, a fuel branch line (L14) may be provided upstream of the heat exchanger (23) in the fuel supply line (L10).

Therefore, the fuel supply unit (20) can transfer at least a portion of the liquid ammonia in the fuel storage tank (10) to the collecting tank (32) upstream of the high-pressure pump (22) and the heat exchanger (23). Therefore, the collecting tank (32) can maintain a state of pressure and temperature at which condensation is possible when gaseous ammonia is introduced.

When the internal pressure of the collecting tank (32) increases, the boiling point of ammonia increases, which is advantageous for liquefaction. In addition, excess ammonia is recovered from the collecting tank (32) to the high-pressure pump (22), and when the internal pressure of the collecting tank (32) is maintained high, the inlet pressure of the high-pressure pump (22) increases, which reduces the possibility of gaseous inflow into the high-pressure pump (22).

In order to increase the internal pressure of the collecting tank (32), the fuel supply unit (20) can transfer at least a portion of the ammonia pressurized by the high pressure pump (22) to the collecting tank (32). That is, in addition to the fuel branch line (L14) being connected from upstream of the heat exchanger (23) to the collecting tank (32), a fuel branch line (L14) can also be connected from downstream of the high pressure pump (22) to the collecting tank (32). However, the former fuel branch line (L14) can be a low pressure line and the latter fuel branch line (L14) can be a high pressure line.

Accordingly, the collecting tank (32) stores some of the surplus high temperature/high pressure liquid ammonia returned from the engine (E), while receiving low temperature/low pressure liquid ammonia upstream of the heat exchanger (23) and additionally receiving high temperature/high pressure liquid ammonia downstream of the high pressure pump (22).

The collecting tank (32) can maintain the internal pressure and internal temperature appropriately by controlling the inflow of liquid ammonia based on various sensors, and when gaseous ammonia branched from the re-liquefaction device (111) flows into the collecting tank (32), condensation of the gaseous ammonia can occur.

Therefore, in this embodiment, since the re-liquefaction device (111) liquefies gaseous ammonia discharged from the fuel storage tank (10) and returns the liquefied ammonia to the fuel storage tank (10), or the re-liquefaction device (111) compresses gaseous ammonia and delivers it to the collecting tank (32), the load of the condenser (113) included in the re-liquefaction device (111) can be reduced.

In addition, the re-liquefaction device (111) can, instead of recovering the liquefied ammonia into the fuel storage tank (10), deliver at least a portion of it to the fuel supply unit (20) by bypassing the fuel storage tank (10). When the liquefied ammonia in the re-liquefaction device (111) flows into the fuel storage tank (10), the pressure is reduced to the internal pressure of the fuel storage tank (10), and at this time, flash gas is generated and gaseous ammonia is regenerated.

On the other hand, the present embodiment can improve the re-liquefaction efficiency by suppressing the generation of flash gas in the fuel storage tank (10) by delivering some of the liquefied ammonia to the heat exchanger (23) instead of injecting it into the fuel storage tank (10) and using it directly as fuel. To this end, the re-liquefaction device (111) has a liquid transfer line (L13) branched from a gas treatment line (L11) connected to the fuel storage tank (10) downstream of the condenser (113). One end of the liquid transfer line (L13) extends downstream of the condenser (113) and the other end is connected to the fuel supply line (L10), so that the liquefied ammonia can be delivered from the fuel supply unit (20) to the upstream of the heat exchanger (23).

FIG. 8 is a conceptual diagram of a fuel processing system according to the eighth embodiment of the present invention.

Referring to FIG. 8, the fuel processing system (1) according to the eighth embodiment of the present invention further includes a boiler (50) that generates steam using ammonia.

At this time, instead of burning ammonia and other fuels (HFO, MGO, LNG, LPG, etc.) to boil water and generate steam, the boiler (50) may be equipped with an oxidation catalyst (52) and utilize the exothermic oxidation reaction of ammonia.

That is, the boiler (50) uses the heat generated by the oxidation reaction of ammonia flowing into the oxidation catalyst (52) to change water into steam using the heat generated by the oxidized ammonia. Therefore, the boiler (50) is provided with an oxidation catalyst (52) together with a steam generator (51).

The boiler (50) can generate steam by receiving ammonia from at least one of the fuel supply unit (20) and the fuel recovery unit (30). For example, the boiler (50) receives ammonia through a fuel supply line (L10) branching from upstream of the low pressure pump (21) in the fuel supply unit (20).

In addition, the gaseous treatment line (L11) through which gaseous ammonia is discharged from the fuel storage tank (10) can also deliver ammonia to the boiler (50). That is, the gaseous treatment line (L11) extends from the fuel storage tank (10) or the pressure control unit (11) (e.g., the re-liquefaction device (111)) toward the boiler (50), so that gaseous ammonia is supplied as fuel to the boiler (50).

The boiler (50) includes a mixer (53). The mixer (53) mixes air into liquid ammonia delivered from a fuel supply unit (20) or a fuel recovery unit (30), or gaseous ammonia delivered from a pressure treatment unit, thereby allowing the ammonia to be delivered to the boiler (50) while maintaining a concentration below the lower explosion limit (LEL).

Conventional boilers using a combustion method must maintain the concentration of ammonia above a certain level, but this embodiment uses an oxidation catalyst (52), so ammonia can be generated even at a low concentration.

Therefore, the present embodiment can eliminate the risk of explosion by diluting the concentration of ammonia flowing into the boiler (50) with air. Accordingly, the area where the boiler (50) of the present embodiment is installed becomes a non-explosion safe area, so that the system can be simplified by applying it to a Gas Safe Machinery Space (a level lower than an ESD-Protected Machinery Safe Space). In addition, the boiler (50) can be installed with non-explosion-proof specifications. In addition, not only the boiler (50), but also all electrical equipment in the room where the boiler (50) is installed can be configured with non-explosion-proof specifications. Furthermore, in cases where human access is restricted, a room equipped for explosion safety may also be unnecessary.

Ammonia can be delivered from the fuel recovery unit (30) to the boiler (50) via the collecting tank (32). That is, the collecting tank (32) can supply at least a portion of the excess ammonia introduced therein to the boiler (50).

The boiler (50) may include a buffer tank (54), which may receive ammonia from the collecting tank (32) and deliver it to the mixer (53) or the boiler (50). Ammonia may flow into the collecting tank (32) when the ammonia fuel supply is normally stopped, and at this time, the ammonia in the collecting tank (32) flows into the boiler (50) via the buffer tank (54).

In addition, the fuel processing system (1) of the present invention can transfer ammonia from the fuel processing unit (60) to the boiler (50). As mentioned above, the fuel processing unit (60) can capture ammonia discharged from the fuel supply unit (20) or the fuel recovery unit (30) during an emergency stop, and the ammonia captured by the fuel processing unit (60) is transferred to the boiler (50) via the mixer (53) when necessary.

However, since the ammonia captured by the fuel treatment unit (60) may be in the form of ammonia water, the ammonia water is delivered to the mixer (53) or boiler (50). In this case, a dryer (not shown) that removes water by vaporization, etc. to convert the ammonia water into ammonia may be provided downstream of the fuel treatment unit (60).

The boiler (50) can heat ammonia flowing into the oxidation catalyst (52) by using high-temperature exhaust gas of 300° C. or higher downstream of the oxidation catalyst (52) to increase steam generation efficiency. At this time, the exhaust gas can be composed of water and nitrogen, etc.

A fuel heat exchanger (55) is provided downstream of the oxidation catalyst (52), and the fuel heat exchanger (55) can heat ammonia flowing into the oxidation catalyst (52) from the mixer (53) by using the high-temperature exhaust delivered from the oxidation catalyst (52) to the steam generator (51).

In this way, the present embodiment generates steam by utilizing heat generated by an oxidation reaction instead of burning ammonia, thereby ensuring that the ammonia flowing into the boiler (50) is below the lower explosion limit (LEL). Accordingly, the boiler (50) can be provided as a non-explosion-proof area, and the space in which the boiler (50) is placed can also be defined as a non-explosion-proof area, thereby excluding explosion-proof equipment and explosion-proof facilities.

FIG. 9 is a conceptual diagram of a fuel processing system according to the ninth embodiment of the present invention.

In the case of FIGS. 9 to 12 below, there are some differences in the configuration compared to FIG. 8, even though they include the boiler (50) mentioned in FIG. 8. Referring to FIG. 9, the fuel processing system (1) according to the ninth embodiment of the present invention includes a preheater (56) and an atomizer (57), compared to the previous eighth embodiment.

The preheater (56) preheats ammonia flowing into the oxidation catalyst (52). In the case of the above-described 8th embodiment, a preheating function can be implemented by including a heater (not shown) upstream of the oxidation catalyst (52), but the preheater (56) of this embodiment is different in that it uses steam generated in a boiler (50) that consumes ammonia.

That is, the preheater (56) of the present embodiment receives at least a portion of the steam discharged from the steam generator (51) other than the amount supplied to the steam consumer. Through this, the preheater (56) can heat the ammonia mixed with air in the mixer (53) before it flows into the oxidation catalyst (52).

As shown in the drawing, the present embodiment can also add a heater between the preheater (56) and the oxidation catalyst (52). As a result, ammonia mixed with air in the mixer (53) can be first preheated by steam, and then secondarily preheated by a heater using any heat source (except steam). The secondarily preheated ammonia is oxidized in the oxidation catalyst (52) and generates heat, thereby contributing to the generation of steam.

On the other hand, the heater may also utilize steam. That is, in this embodiment, ammonia is discharged from the mixer (53) and then first preheated by steam in the preheater (56), and then secondarily preheated by steam in the heater. At this time, the amount of steam supplied from the steam generator (51) to the preheater (56) and the heater can be actively controlled based on the temperature of the ammonia, the required temperature/amount of steam, etc.

FIG. 10 is a conceptual diagram of a fuel processing system according to the tenth embodiment of the present invention.

Referring to FIG. 10, in the fuel processing system (1) according to the 10th embodiment of the present invention, a preheater (56) can be provided upstream of a mixer (53) as compared to the 9th embodiment.

The preheater (56) can preheat ammonia flowing into the mixer (53) using steam generated from the boiler (50). At this time, the ammonia preheated by the preheater (56) may be liquid ammonia discharged from the fuel storage tank (10), and may be at least a portion of the ammonia to be supplied to the fuel supply unit (20).

In addition, unlike in the drawing, the preheater (56) can also preheat gaseous ammonia delivered from a fuel storage tank (10) or a pressure control unit (11). In this case, the gaseous delivery line (L12) can join the liquid ammonia upstream of the preheater (56). That is, the gaseous delivery line (L12) is connected upstream of the preheater (56) from the fuel supply line (L10).

FIG. 11 is a conceptual diagram of a fuel processing system according to the 11th embodiment of the present invention.

Referring to FIG. 11, a fuel processing system (1) according to the 11th embodiment of the present invention has a buffer tank (54) that receives ammonia delivered from at least a portion of a fuel supply unit (20) and a fuel recovery unit (30) and delivers it to a mixer (53) or a boiler (50).

This embodiment may be similar to the eighth embodiment in that the buffer tank (54) delivers ammonia to the mixer (53), etc., but in the case of the previous eighth embodiment, ammonia discharged from a normal stop or an emergency stop, etc. is used, while this embodiment may use ammonia in the purging gas discharged during purging.

As will be described below with reference to FIG. 15, etc., the present invention may include a purging unit (70). The purging unit (70) is configured to purge the fuel supply unit (20) and the fuel recovery unit (30) using a purging gas, which is a non-explosive gas such as an inert gas or nitrogen.

During the purging process, ammonia remaining in at least a portion of the fuel supply unit (20) and the fuel recovery unit (30) is discharged together with the purging gas, and at this time, the ammonia discharged together with the purging gas can be transferred to the buffer tank (54).

The purging gas/ammonia delivered to the buffer tank (54) can be delivered from the collecting tank (32) provided in the fuel recovery unit (30). Since the collecting tank (32) maintains a constant pressure (approximately 20 bar), if the pressure rises above that during purging, ammonia and purging gas, etc. can be discharged. At this time, in order to prevent overpressure, the ammonia/purging gas discharged from the collecting tank (32) can be delivered to the buffer tank (54). The buffer tank (54) supplies the ammonia delivered from the collecting tank (32) to the boiler (50), so that the collecting tank (32) can maintain a constant pressure despite purging.

However, in this embodiment, the buffer tank (54) may be omitted, in which case the ammonia/purging gas discharged from the collecting tank (32) to relieve overpressure may be delivered to the mixer (53). At this time, the mixer (53) can dilute a smaller amount of air compared to other embodiments, considering that the ammonia has already been diluted by the purging gas.

In addition, in this embodiment, if the buffer tank (54) is omitted, ammonia from the collecting tank (32) is delivered to the fuel processing unit (60), and ammonia water collected in the fuel processing unit (60) can be delivered to the mixer (53). As a reference, ammonia water can be supplied to the mixer (53) after water is separated through vaporization treatment, which will be described later.

FIG. 12 is a conceptual diagram of a fuel processing system according to the 12th embodiment of the present invention.

Referring to FIG. 12, a fuel processing system (1) according to the 12th embodiment of the present invention supplies ammonia to a boiler (50) using a fuel processing unit (60).

The fuel treatment unit (60) can receive and capture ammonia discharged from the fuel supply unit (20) and the fuel recovery unit (30). The fuel treatment unit (60) can dissolve ammonia in water and capture it in the form of ammonia water.

At this time, ammonia water generated by the fuel processing unit (60) is supplied to the mixer (53) or boiler (50). However, in the present embodiment, instead of directly delivering a mixture of ammonia and water to the mixer (53), water may be removed and only ammonia may be delivered to the mixer (53).

For this purpose, a dryer (not shown) may be provided between the fuel processing unit (60) and the mixer (53), and the dryer may have a vaporization function, as described above in the 8th embodiment.

Therefore, ammonia discharged from the fuel supply unit (20) and delivered to the fuel processing unit (60) takes the form of ammonia water dissolved in water, but is delivered to the mixer (53) after the water is removed through vaporization or the like.

Additionally, in the present embodiment, when urgently purging the inside of the engine (E) in an ESD (Emergency Shutdown) state, if a line or valve returning to the collecting tank (32) fails and does not allow the flow of ammonia, the purging gas may be sent to the fuel processing unit (60) so that ammonia may be captured by the fuel processing unit (60).

That is, in this embodiment, the fuel processing unit (60) can capture ammonia discharged from the fuel supply unit (20) or the like when the system is stopped and transfer it to the mixer (53), or capture ammonia/purging gas discharged from the fuel recovery unit (30) or the like when the system is purged and transfer it to the mixer (53).

For reference, although the present invention has shown the lines through which ammonia flows during discharge and purging separately, the discharge line (L40) and the purging line (L50) may be shared at least in part. That is, as described above, ammonia delivered through the discharge line (L40) or the purging line (L50) may be delivered to the mixer (53) via the fuel treatment unit (60), while the collecting tank (32) may also perform the function of delivering ammonia delivered through the discharge line (L40) in addition to the purging line (L50) to the mixer (53).

In addition, in this specification, discharge is a process for removing ammonia remaining in a line through which ammonia flows, and purging is a process for cleaning a line through which ammonia flows with an inert gas, and purging can be performed continuously after discharge.

In this case, in the case of discharge, ammonia is delivered to the fuel treatment unit (60) for recycling as fuel, while in the case of purging, ammonia can be delivered to the collecting tank (32) for discharge treatment. However, as mentioned above, the present invention can change the above part as much as desired.

FIGS. 13 and 14 are conceptual diagrams of a fuel processing system according to a 13th embodiment of the present invention.

FIG. 13 is a conceptual diagram of a plurality of fuel processing units (60) that can be equipped in a fuel processing system (1) according to the 13th embodiment of the present invention, and FIG. 14 compares the performances of the fuel processing units (60) shown in FIG. 13.

Referring to FIGS. 13 and 14, the fuel processing system (1) according to the 13th embodiment of the present invention may include at least one of a scrubber (61) and an absorption tank (62) as a fuel processing unit (60). This has been described previously in FIG. 1 and the like.

The fuel treatment unit (60) captures ammonia emitted from the fuel supply unit (20) or the fuel recovery unit (30) during discharge or purging. Since ammonia is a toxic substance, it is prohibited to be emitted into the atmosphere above a certain concentration. Therefore, the fuel treatment unit (60) captures ammonia emitted from the fuel supply unit (20) and prevents it from being emitted into the atmosphere.

Since ammonia has the property of dissolving in water, the fuel treatment unit (60) can capture ammonia using water. The fuel treatment unit (60) uses at least one of a method of spraying water onto ammonia or a method of injecting ammonia into water.

To utilize the former method, the fuel treatment unit (60) may include a scrubber (61), and to utilize the latter method, the fuel treatment unit (60) may include an absorption tank (62).

The scrubber (61), as shown in Fig. 13(A), has a space into which ammonia flows in, and can spray water into the space. When water is sprayed onto ammonia, the ammonia dissolves in the water and changes into ammonia water. Accordingly, ammonia water can be generated at the bottom of the scrubber (61), and the ammonia water is discharged through the outlet at the bottom of the scrubber (61).

As shown in Fig. 14(A), the scrubber (61) can have a constant ammonia capturing performance when the ammonia flow rate is constant, and when the ammonia flow rate changes and the flow rate of water flowing into the scrubber (61) does not change appropriately, the ammonia capturing performance can deteriorate. In other words, the scrubber (61) can be used when the ammonia flow rate is constant.

That is, the scrubber (61) has a disadvantage in that the performance is not constant when the injection flow rate of ammonia changes while maintaining the flow rate of water sprayed inside the scrubber (61) constant. On the other hand, it is not easy to adjust the spray amount of water by considering the injection flow rate of ammonia and is not desirable in terms of cost.

The absorption tank (62) stores a certain amount of water inside, as shown in Fig. 13(C). Ammonia can be injected into the water in the absorption tank (62), and the injected ammonia dissolves in the water. Accordingly, the water stored in the absorption tank (62) changes into ammonia water, and the ammonia concentration of the ammonia water can gradually increase depending on the amount of ammonia injected.

Since the absorption tank (62) uses a certain amount of stored water, as shown in Fig. 14(C), as the amount of ammonia injected increases, the ammonia concentration inside increases and, conversely, the absorption performance inevitably decreases. In other words, unless water is continuously circulated in the absorption tank (62), the absorption tank (62) has a limit to its ammonia absorption function. Accordingly, if ammonia exceeding a certain concentration is absorbed in the absorption tank (62), the ammonia water inside may need to be discarded and new water may need to be added.

In order to overcome the respective shortcomings of the scrubber (61) and absorption tank (62) described above, the fuel processing unit (60) may have an integrated form of the scrubber (61) and absorption tank (62), as shown in Fig. 13(B).

In this case, a scrubber (61) is provided at the top and an absorption tank (62) is provided at the bottom. Ammonia is injected into the water stored in the absorption tank (62). If the ammonia capture performance of the ammonia water in the absorption tank (62) is low, ammonia is not absorbed in the absorption tank (62) and moves upward. At this time, ammonia can be additionally captured using water sprayed from the scrubber (61).

In the case where the scrubber (61) and the absorption tank (62) are integrated, the initial high flow rate of ammonia can be responded to through the absorption tank (62) as in Fig. 14(B). In addition, if only the absorption tank (62) is used, the ammonia absorption performance deteriorates after the initial stage, but in this case, the ammonia absorption performance after the initial stage can be supplemented by using the scrubber (61).

If the scrubber (61) and the absorption tank (62) are provided as an integrated unit, both large-capacity absorption of ammonia using the absorption tank (62) and continuous capture of ammonia using the scrubber (61) can be achieved. However, in order to be used in combination with the scrubber (61), there is a limitation that the absorption tank (62) must be prepared in a large capacity considering the amount of water sprayed from the scrubber (61).

To improve this, the fuel processing unit (60) may be provided with multiple absorption tanks (62) as in Fig. 13(D). That is, the fuel processing unit (60) is provided with multiple absorption tanks (62) that capture ammonia using water and generate ammonia water.

At this time, a plurality of absorption tanks (62) may be arranged in multiple stages. Accordingly, ammonia discharged from the fuel supply unit (20), etc., passes through the plurality of absorption tanks (62) in sequence. That is, ammonia may be dissolved in an absorption tank (62) arranged upstream among the plurality of absorption tanks (62) and changed into ammonia water, or may be dissolved in an absorption tank (62) arranged downstream and changed into ammonia water.

Accordingly, the plurality of absorption tanks (62) can have a relatively lower ammonia concentration from upstream to downstream based on the flow of ammonia discharged from the fuel supply unit (20) or the fuel recovery unit (30).

A plurality of absorption tanks (62) can be stacked in the height direction so that gas not absorbed in the lower absorption tank (62) is transferred to the upper absorption tank (62). To this end, a line (not shown) for transferring ammonia into water in another absorption tank (62) provided above one absorption tank (62) can be provided. This line can sequentially connect the absorption tanks (62).

For example, a plurality of absorption tanks (62) have a first absorption tank (62) in which water is stored inside and ammonia discharged from a fuel supply unit (20) or a fuel recovery unit (30) flows into the water, and a second absorption tank (62) provided above the first absorption tank (62). The second absorption tank (62) also has water stored inside like the first absorption tank (62), and gas that was not absorbed into water in the first absorption tank (62) can flow into the second absorption tank (62).

Additionally, the fuel processing unit (60) may include an nth absorption tank (62). The nth absorption tank (62) may be a second absorption tank (62) or a third absorption tank (62), and in the case of the drawing, may be a sixth absorption tank (62).

The nth absorption tank (62) stores water inside and receives gas that was not absorbed into water in at least the first absorption tank (62) among the first absorption tank (62) and the second absorption tank (62). In other words, the nth absorption tank (62) can receive gaseous ammonia that was not captured in the n-1th absorption tank (62).

Since the fuel treatment unit (60) can be equipped with a total of n absorption tanks (62), gaseous ammonia that is not captured in water in the nth absorption tank (62) can be released into the atmosphere at a concentration below a certain level. That is, the fuel treatment unit (60) is equipped from the first absorption tank (62) to the nth absorption tank (62), and the nth absorption tank (62) forms the final stage of ammonia capture. Therefore, the nth absorption tank (62) must process the ammonia that is not captured by itself, and at this time, gaseous ammonia is released into the atmosphere from the nth absorption tank (62) within a range in which atmospheric release is permissible.

The plurality of absorption tanks (62) included in the fuel processing unit (60) may be provided so as to be separable from each other. In addition, the plurality of absorption tanks (62) may be stacked in a vertical direction, or may be arranged in a direction other than vertical if there is no problem with the transmission of gaseous ammonia.

Alternatively, a plurality of absorption tanks (62) may be arranged spaced apart from each other without structural contact or connection, and may be connected only through lines so that they can be easily separated from each other.

In this case, the absorption tanks (62) are provided so that they can be disposed of separately. That is, the first absorption tank (62) located most upstream from the fuel treatment unit (60) reaches a certain ammonia concentration earlier than the second absorption tank (62) located downstream. If the internal ammonia concentration of the first absorption tank (62) rises to a concentration requiring disposal, the first absorption tank (62) can be separated from the second absorption tank (62) and disposed of separately.

In this case, ammonia discharged from the fuel supply unit (20), etc., can be directly introduced into the second absorption tank (62). To this end, the discharge line (L40) can be connected to the second absorption tank (62) after being separated from the first absorption tank (62) when the first absorption tank (62) is removed.

Alternatively, the discharge line (L40) may be connected to the first absorption tank (62) to the nth absorption tank (62), respectively, and may be opened only to the first absorption tank (62), and may be switched so that when the first absorption tank (62) is disposed of, the flow to the first absorption tank (62) is blocked and the flow is opened only to the second absorption tank (62).

In this case, when multiple absorption tanks (62) are used, the overall ammonia absorption performance may gradually decrease as shown in Fig. 14(D), but initial large-capacity ammonia capture is possible without a problem.

In addition, the ammonia concentration is different for each absorption tank (62), and when a high-concentration absorption tank (62) is discarded, the ammonia concentration decreases throughout the fuel treatment unit (60). Therefore, the fuel treatment unit (60) can ensure smooth capture of ammonia until all absorption tanks (62) are discarded.

Therefore, the fuel processing unit (60) using the form of Fig. 13(D) has solved the existing problem of ammonia capture performance rapidly deteriorating when the ammonia concentration of water stored in the absorption tank (62) increases.

FIG. 15 is a conceptual diagram of a fuel processing system according to the 14th embodiment of the present invention.

Referring to FIG. 15, a fuel processing system (1) according to the 14th embodiment of the present invention has a purging unit (70) that implements purging using a collecting tank (32).

The purging unit (70) injects a purging gas such as an inert gas or nitrogen into the purging target section before and after the engine (E). The purging target section may include the section between the FVT and the engine (E), a portion upstream of the SVT, a portion downstream of the RVT, etc., but there is no particular limitation thereto.

The purging unit (70) injects purging gas into the fuel supply unit (20) so that ammonia remaining in the purging target area is removed. The purging gas injected into the fuel supply unit (20) flows together with the ammonia remaining in the fuel supply unit (20) and passes through the engine (E) and then moves to the fuel recovery unit (30). Thereafter, the purging gas and ammonia can be introduced into the collecting tank (32) provided in the fuel recovery unit (30).

The collecting tank (32) can store purging gas and ammonia and discharge them when necessary. The collecting tank (32) can discharge ammonia into the atmosphere at a concentration below a certain level. At this time, the ammonia discharged from the collecting tank (32) can be discharged into the atmosphere via a discharge mast.

On the other hand, ammonia flowing into the collecting tank (32) during purging may be transferred to the fuel treatment unit (60) and processed. At this time, the fuel treatment unit (60) receives the purging gas and ammonia flowing into the collecting tank (32) and absorbs the ammonia into water. As previously explained through FIG. 8, etc., the fuel treatment unit (60) can then supply ammonia water to the boiler (50), etc.

It is also possible for ammonia to be delivered directly from the collecting tank (32) to the discharge mast, or ammonia may be discharged into the atmosphere through the fuel treatment unit (60) from the collecting tank (32). The fuel treatment unit (60) captures ammonia using water to generate ammonia water, and as already explained in FIG. 13, etc., ammonia below a certain concentration can be discharged to the outside.

However, in this embodiment, by utilizing the purging drum (71) and the purging compressor (72) provided in the purging unit (70), the atmospheric emission of ammonia through the collecting tank (32) or the fuel processing unit (60) can be suppressed or omitted.

The purging drum (71) delivers the purging gas to the fuel supply unit (20). The purging drum (71) can be placed between the purging compressor (72) and the fuel supply unit (20), and temporarily stores the purging gas compressed by the purging compressor (72) and then injects it into the fuel supply unit (20).

The purging compressor (72) compresses the purging gas. Specifically, the purging compressor (72) compresses the purging gas and injects it into the fuel supply unit (20), so that the ammonia remaining in the purging target section before and after the engine (E) is transferred to the collecting tank (32).

For this purpose, the purging unit (70) is equipped with a purging line (L50). The purging line (L50) connects the collecting tank (32) and the purging compressor (72), and is connected from the purging compressor (72) to the fuel supply unit (20) so that the purging gas flows into the fuel supply unit (20), and can also be connected from the fuel recovery unit (30) to the purging compressor (72) via the collecting tank (32).

In addition, the purging compressor (72) sucks in the purging gas injected into the purging target section when purging is completed for the purging target section and transfers it to the collecting tank (32). To this end, the purging line (L50) can be connected from the fuel recovery unit (30) to the collecting tank (32) via the purging compressor (72).

That is, the purging unit (70) of the present embodiment can switch the flow of the purging gas to the purging target section and the collecting tank (32) before and after purging. For example, the purging compressor (72) compresses the purging gas stored in the collecting tank (32) during purging. The purging compressor (72) transfers the compressed purging gas to the purging drum (71), and the purging gas introduced into the purging drum (71) is injected into the fuel supply unit (20). In this case, the ammonia remaining in the purging target section is transferred to the collecting tank (32) together with the purging gas. This is as shown in the upper and center of Fig. 15.

Afterwards, when purging is completed for the purging target section, the inflow from the fuel recovery unit (30) to the collecting tank (32) is blocked by a valve or the like. At this time, the purging compressor (72) sucks in the purging gas stored in the purging target section and the purging drum (71) and transfers it to the collecting tank (32), as shown in the lower part of Fig. 15.

Therefore, the collecting tank (32) receives the purging gas before purging, and then receives and stores the ammonia remaining in the purging target area during purging. In this case, since ammonia is filled as much as the purging gas is discharged, the internal pressure can be constant or slightly increased.

When purging is completed, the collecting tank (32) stores the purging gas in addition to the ammonia that was filled inside. In this case, the collecting tank (32) may be slightly pressurized, while the purging target area may be depressurized due to the suction of the purging gas by the purging compressor (72).

After purging is completed and the purging gas is completely delivered to the collecting tank (32), the purging gas remaining in the purging target area is recovered to the collecting tank (32), and then the ammonia stored in the collecting tank (32) is recycled as fuel for the engine (E). Accordingly, the collecting tank (32) returns to a state where it mainly stores the purging gas, so it can be prepared for purging again.

In such a case, the present embodiment enables smooth purging of the purging target section without atmospheric discharge through the aforementioned exhaust mast.

However, for this purpose, the purging line (L50) is provided so that the relationship between the purging compressor (72), the collecting tank (32), and the purging drum (71) can be connected in the forward and reverse directions. For example, the purging line (L50) is provided so that a first flow flow from the collecting tank (32) to the purging drum (71) via the purging compressor (72) and a second flow flow from the purging drum (71) to the collecting tank (32) via the purging compressor (72) are selectively implemented.

That is, the purging line (L50) can implement a first flow that connects the inlet end of the purging compressor (72) to the collecting tank (32) and the discharge end of the purging compressor (72) to the purging drum (71). Alternatively, the purging line (L50) can implement a second flow that connects the inlet end of the purging compressor (72) to the purging drum (71) and the discharge end of the purging compressor (72) to the collecting tank (32).

The first flow stream is a purging gas stored in a collecting tank (32), which is sucked into a purging compressor (72), compressed, and then injected into a purging target section through a purging drum (71). At this time, ammonia remaining in the purging target section flows into the collecting tank (32).

On the other hand, the second flow stream is such that the purging gas in the purging target section is sucked into the purging compressor (72) through the purging drum (71), and then compressed and flows into the collecting tank (32). At this time, since the collecting tank (32) contains residual ammonia, the internal pressure may increase somewhat as the purging gas is additionally injected.

In this embodiment, ammonia can be safely discharged from the collecting tank (32) to the discharge mast via the fuel treatment unit (60) during purging. Alternatively, in this embodiment, by utilizing the purging compressor (72), the purging drum (71), and the collecting tank (32), the purging gas and residual ammonia for the purging target section are all treated into the collecting tank (32). Therefore, in this embodiment, the transfer of ammonia from the collecting tank (32) to the discharge mast can be omitted or minimized.

The present invention encompasses, in addition to the embodiments described above, combinations of the embodiments and embodiments resulting from a combination of at least one embodiment and a known technology.

Although the present invention has been described in detail through specific examples, this is intended to specifically explain the present invention, and the present invention is not limited thereto, and it will be apparent that modifications or improvements can be made by those skilled in the art within the technical spirit of the present invention.

All simple modifications or changes of the present invention fall within the scope of the present invention, and the specific protection scope of the present invention will be made clear by the appended claims.

1: Fuel handling system E: Engine
10: Fuel storage tank 11: Pressure control unit
111: Reliquefaction device 112: Compressor
113: Condenser 20: Fuel supply section
21: Low pressure pump 22: High pressure pump
23: Heat exchanger 30: Fuel recovery unit
31: Cooler 32: Collecting Tank
40: Exhaust treatment unit 41: SCR
42: Metering unit 43: Air supply unit
44: Ammonia transfer unit 45: Return heat exchanger
46: Transfer heat exchanger 47: Vaporizer
48: Ammonia/Air Mixer 50: Boiler
51: Steam generator 52: Oxidation catalyst
53: Mixer 54: Buffer Tank
55: Fuel heat exchanger 56: Preheater
57: Atomizer 60: Fuel treatment unit
61: Scrubber 62: Absorption tank
70: Purging section 71: Purging drum
72: Compressor for purging L10: Fuel supply line
L11: Weather processing line L12: Weather transmission line
L13: Liquid delivery line L14: Fuel branch line
L20: Fuel recovery line L30: Fuel delivery line
L31: Fuel return line L40: Discharge line
L50: Purging line

Claims (7)

A fuel supply unit that supplies fuel discharged from a fuel storage tank to a demand source;
A fuel recovery unit for recovering surplus fuel returned from the above demand source; and
A fuel treatment unit is included for capturing fuel vented from the fuel supply unit or the fuel recovery unit.
The above fuel processing unit,
Contains a plurality of absorption tanks that capture fuel using water and produce waste water;
Fuel vented from the fuel supply unit or the fuel recovery unit passes through the plurality of absorption tanks in sequence and is dissolved in the water stored in the absorption tanks to change into wastewater.
The above multiple absorption tanks,
A first absorption tank having water stored therein and into which fuel vented from the fuel supply unit or the fuel recovery unit flows through a discharge line; and
It includes a second absorption tank in which water is stored inside and into which gas that was not absorbed into the water in the first absorption tank flows,
The above discharge line,
A fuel processing system, which is additionally connected to the second absorption tank separately from the first absorption tank, so that the second absorption tank supplies or captures the fuel independently of the first absorption tank. In the first paragraph, the plurality of absorption tanks,
A fuel treatment system having a relatively lower fuel concentration from upstream to downstream based on the flow of fuel vented from the fuel supply unit or the fuel recovery unit. In the first paragraph, the plurality of absorption tanks,
A fuel processing system in which the absorption tanks are stacked in the height direction and each absorption tank is provided so as to be separated. In the first paragraph, the first absorption tank,
A fuel treatment system provided below the second absorption tank, wherein the fuel concentration in the wastewater is separated based on the second absorption tank when the fuel concentration in the wastewater is above a certain level. In the first paragraph, the fuel processing unit,
A fuel processing system comprising an nth absorption tank, wherein water is stored therein, gas that is not absorbed into water in at least the first absorption tank and the second absorption tank is introduced therein, and gas that is not absorbed into water inside is discharged to the atmosphere at a concentration below a predetermined level. A vessel having the fuel processing system according to any one of claims 1 to 5. delete

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